Circular saws, particularly portable direct drive circular saws, have seen great commercial success because of their adaptability, reliability, power, convenience, and safety in cutting plywood, paneling or other flat surfaced woods.
Most direct drive circular saws have a blade guard housing and a pivotally mounted lower blade guard housing. The saw blade is mounted on an motor driven arbor. The motor is mounted within a motor housing adjacent the upper guard housing. The motor operably drives a cooling fan. A motor housing about the motor and fan has an inlet an exhaust vent for directing cooling air through the motor housing and about the motor. A foot having an opening therethrough is mounted about the circular saw blade for providing a platform on which the circular saw rests on the wood that is being cut.
The foot has a front lead guide for providing a visual alignment guide for indicating the linear alignment where the circular saw will cut into the wood. Many operators use this lead guide solely or in conjunction with the position of the saw blade to determine the alignment of the saw and properly guide the saw blade through the wood.
A common problem with circular saws is the fact that after a sufficient amount of saw dust is created by the cutting action of the saw blade, the saw dust often obscures the lead guide. An operator of the circular saw finds that he repeatedly either stops the saw to wipe away the saw dust or backs the saw off momentarily while he puckers his lips and manually blows the dust off. Either procedure wastes time and lowers the efficiency of the circular saw operation.
To date, circular saws have been developed and built without effective and economical blowers that clear most of the saw dust away from the aligned cutting path and maintain a visually clear path for the operator. The built-in systems use suction and mount a bag to collect the saw dust. The mount and bag add expense and while it collects much saw dust, it does not specifically address the problem of saw dust collecting upon and obscuring the lead guide.
The only known blowers use a complex flexible rubber conduit assembly that needs to be bracketed and clamped at its outlet end to maintain its appropriate position. See U.S. Pat. No. 5,084,971 to Remington et al. The rubber conduits and extra wire brackets make it inconvenient to use. Furthermore, many saws do not have threaded apertures about its exhaust vent that allows a plenum to be mounted thereto. As such, many people continue to blow the saw dust away with their breath.
What is needed is a economically feasible retrofit device that automatically and continuously blows the saw dust off the visual lead guide of a direct drive circular saw thereby eliminating the need for the operator to stop and clear the lead guide by wiping it or blowing air from his mouth. What is also needed is a blower device that can easily attach to a wide variety of present models as a retrofit accessory without the use of wire clamping devices or additional mounting screws embedded through the exhaust vent.